who still seals balsa for laminating?

General Discussion
1

who still seals balsa for laminating?

I’m finally ready to start laminating my balsa skinned compand and wondering if I should seal the balsa first or not?

 

Before vac-bagging the deck skin on I sealed the balsa with a thinned coat of resin to reduce the amount of resin the balsa absorbed. Who is still doing it and it is worth it? I know folks where going back and forth and am now wondering what the consensus is now.

 

please share

 

2

I do inner before vacuuming on, and the outer before lamming. Just insurance really

 

3

Hey Karl,

Thanks, how much resin do you use to seal what length board? I think I used 3 oz of epoxy with 1 oz of rubbing alcohol when I sealed the inside but can’t remember for sure.

This was for a 6’8"x22". When sealing the bottom before laminating how far around the rail do you seal? just where the bottom glass will touch or do you paint underneath onto the deck area?

Have a Gold Medal Day!

 

4

My last balsa was 6’ x 19.5" and I used 122 gms of epoxy heated up for deck, bottom and rails, all in one go.

I then lam within a few hours (using RR with fast hardner)

K

5

sealing the surface to my judgement is primary.

wether you use wood or foam

of any kind this remains the same.

thinning is likely to increase the chance

of faulty mixing and irregular coat.

R.R. goes a long way

maybe an ounce to the foot

always adjustable to taste

or thickness.

The ‘Hairy’ quality of

core materials balsa or styrofoam 

has impressed me how well

it takes a seal and sand,

I sand with 60 grit 

to eliminate all cloth catching barbs

and still provides a ‘mechanical bond’

surface par excelent.

This alone reduces the amount

of available pores to soak resin.

 

applied with a vigorous squeegee technique

working the resin as deep as possible into the blank

material pores is essential. I am also

quite comfortable adding a little q- cell-aerosil white pigment

mixture filler to the styro core.As to the balsa question

I use resin and aerosil alone to preserve the color…

 

I have consistently laminated fiberglass cloth over filler.

 

I am concerned about the integrity of thinning

the resin.

 

…ambrose…

as I am working in a warmer climate

my results bear directly on temperatures over 70…

6

While not Balsa, here is a wood seal I did a few years back.......Is this what you are talking about Forest?

 

I built this as a monument to the movement of the DOAS (death Of All Seals).  You can't tell scale, but it's actually 24 ft high.

7

Use a weenie roller to apply the epoxy. it will give a light coat and make the epoxy go a lot further.  if you brush or squeegee you will use 2x as much epoxy.

Also just roll it fast then go back over it.  A little epoxy will will bond a long way. I mean, if you sit in one spot and work the epoxy till the wood looks wet, you have used way too much.  Get the material out fast and thin, let it sit, then go over it again.  If you have any left over epoxy...get rid of it, don't pour it on the board thinking "Heck I'll just use up what's left"  All those little "I'll just use up what's left" add up to makes a big, fat, heavy surfboard